A comparison of emotional and cognitive intelligences in people with and without temporal lobe epilepsy
Address correspondence to Claire Isaac, Clinical Lecturer, Clinical Psychology Unit, Department of Psychology, University of Sheffield, Western Bank, Sheffield, S10 2TN, U.K. E-mail: C.L.Isaac@sheffield.ac.uk
Medial temporal lobe structures have been hypothesized to be important in emotional intelligence (EI) and social cognition. There is some evidence associating temporal lobe epilepsy (TLE) with impairments in social cognition. This study aimed to establish whether TLE is also associated with deficits in EI. Sixteen patients with TLE and 14 controls without epilepsy matched for age and current intelligence quotient were compared on measures of EI, recognition of facial expressions of emotion, and distress. Results indicated that patients with TLE showed both impaired EI and impaired recognition of facial expressions. They also reported greater psychological distress, which correlated negatively with EI. It is suggested that some of the psychosocial problems experienced by patients with TLE can be conceptualized as the consequences of deficits in EI, possibly resulting from epilepsy-related disruption to medial temporal lobe functioning.
Temporal lobe epilepsy (TLE) is associated with cognitive impairments (Oyegbile et al., 2004) and psychosocial difficulties including depression, social anxiety, the subjective experience of stigma, feelings of isolation and relationship problems (Moore & Baker, 2002). Despite many years of speculation, it remains unclear to what extent psychosocial difficulties are related to the fact that patients are living with a chronic and stigmatizing condition and to what extent they are related to neuropathology.
A resurgence of interest in this question has been stimulated by the emergence of the field of social cognitive neuroscience, which aims to identify the neurological structures underlying social behavior. Social cognitive abilities include skills involved in recognizing, manipulating, and behaving in respect to socially relevant information and are hypothesized to be mediated by a network of interconnected brain regions including the amygdala, cingulate cortex, orbitofrontal cortex, and right somatosensory cortex (Adolphs, 2001). There is emerging evidence of social cognition deficits in people with TLE similar to those reported in patients with structural damage to these brain regions. Thus, TLE has been associated with abnormalities in both recognition of facial expressions of fear (Reynders et al., 2005; Shaw et al., 2007) and performance on a theory of mind task (Schacher et al., 2006; but see Shaw et al., 2007).
Emotional Intelligence (EI), a concept related to that of social cognition, was first formally defined by Salovey & Mayer (1990). EI includes discriminating among and monitoring one's own feelings and those of others and using this information to guide responding. In the first study of its kind Bar On et al. (2003) reported that a group of patients with damage to brain regions proposed to underlie social cognition was impaired on a measure of EI in comparison with a group of patients with damage elsewhere, despite the fact that groups were matched for cognitive intelligence. Gawryluk & McGlone (2007) also reported significantly lower EI than cognitive intelligence quotient (IQ) in people who had undergone amygdalohippocampectomy or anterior temporal lobectomy for intractable TLE. It is not clear whether this deficit existed presurgically, however. These findings raise the possibility that psychosocial difficulties in TLE may be conceptualized as deficits in EI, related to specific neuropathology previously proposed to underlie social cognition.
The first aim of the current study is to compare EI scores of patients with TLE to those of matched controls to investigate the possibility that TLE is associated with a specific deficit in EI. The second aim is to assess whether performance on a social cognition task related to amygdala function and compromised in TLE is related to EI. The third is to investigate the possibility that EI is related to psychological distress and quality of life in patients with TLE.
Demographic and epilepsy-related details of participants are provided in Table 1.
Table 1. Demographic information for TLE and control groups seizure related information for TLE groups
|TLE|| 1||F||46||LMTS||46||72||104||122||85|| 9||6||9|
| 3||F||50||LTL tumor|| 1|| 1||108||116||87|| 4||6||1|
| 4||F||21||RMTS||21||104 || 85|| 98||78||15||11 ||9|
| 5||F||52||RMTS||52||13|| 99||117||101 ||16||4||2|
| 6||F||44||RMTS||42||39||104||120||60|| 7||12 ||5|
| 7||F||42||RMTS||42||52|| 96||107||77||16||6||2|
| 8||M||54||LMTS||50||52||114||121||102 || 4||4||2|
| 9||M||25||LMTS||16|| 1|| 89|| 99||77||17||7||2|
|11||M||65||LTL cavernoma||57||156 || 91||102||81||13||8||3|
|14||M||48||RMTS||20||52|| 98||100||75|| 6||13 ||3|
|15||M||35||RMTS||21|| 2||102|| 95||71||17||8||7|
|16||M||63||RTL cavernoma|| 4||19|| 97||109||76||10||7||6|
|TLE|| ||F = 7||45.31|| || || ||99.06||107.31||79.00||13.06||7.19||3.94|
|(N = 16)|| ||M = 9||(11.81)|| || || ||(9.38)||(9.08)||(15.36)||(6.22)||(3.47)||(2.84)|
|Control|| ||F = 8||43.86|| || || || ||114.07||100.29||8.79||4.71||1.57|
|(N = 14)|| ||M = 6||(10.92)|| || || || ||(12.33)||(15.36)||(4.21)||(2.70)||(1.22)|
|p = 0.73|| || || || ||t =−1.72,||t = 3.79,||t = 2.17,||t = 2.16,||t = 2.89,|
| || || || || ||p = 0.10||p < 0.001||p = 0.039||p = 0.040||p = 0.006|
This comprised 16 participants aged 18–75. Diagnosis of TLE was confirmed by neurological investigation, electroencephalography, and magnetic-resonance imaging. No patient had undergone epilepsy surgery, had any history of head injury, oxygen deprivation, diagnosis of psychiatric illness (excluding anxiety and depression), personality disorder, other neurological illness, or autistic spectrum disorder. All participants were English-speaking.
This comprised 14 participants who responded to advertisements. Inclusion criteria were as for the TLE group but no participants had ever experienced a seizure.
Wechsler Test of Adult Reading UK (WTAR; Wechsler, 2001) provided an estimate of premorbid cognitive intelligence.
Wechsler Abbreviated Scale of Intelligence (WASI; Wechsler, 1999) provided a standardized measure of current cognitive intelligence (Full Scale IQ [FSIQ]).
Hospital Anxiety and Depression Scale (HADS; Zigmond & Snaith, 1983) provided information about current levels of anxiety and depression.
Emotional Quotient Inventory (EQ-i) (Bar On, 1997) provided a measure of EI based on self report. The EQ-i comprised 133 statements to which participants responded on a scale from 1 (“very seldom or not true of me”) to 5 (“very often or true of me”). This yielded a total EQ. (See Table 2 for detailed description.)
Table 2. Descriptions of the domains and subscales of the EQi
|Adaptability EQ||Flexibility||The ability to adjust one's emotions, thoughts and behavior to changing situations and conditions.|
|Problem solving||The ability to identify and define problems as well as to generate and implement potentially effective solutions.|
|Reality testing||The ability to assess the correspondence between what is experienced and what objectively exists.|
|General Mood EQ||Happiness||The ability to feel satisfied with one's life, to enjoy oneself and others, and to have fun.|
|Optimism||The ability to look at the brighter side of life and to maintain a positive attitude, even in the face of adversity.|
|Interpersonal EQ||Empathy||The ability to be aware of, to understand, and to appreciate the feelings of others.|
|Interpersonal relationship||The ability to establish and maintain mutually satisfying relationships that are characterized by intimacy and by giving and receiving affection.|
|Social responsibility||The ability to demonstrate oneself as a cooperative, contributing, and constructive member of one's social group.|
|Intrapersonal EQ||Assertiveness||The ability to express feelings, beliefs, and thoughts and defend one's rights in a nondestructive manner.|
|Emotional self-awareness||The ability to recognize one's feelings.|
|Independence||The ability to be self-directed and self-controlled in one's thinking and actions and to be free of emotional dependency.|
|Self-actualization||The ability to realize one's potential capacities.|
|Self-regard||The ability to respect and accept oneself as basically good.|
|Stress Management EQ||Impulse control||The ability to resist or delay an impulse, drive, or temptation to act.|
|Stress tolerance||The ability to withstand adverse events and stressful situations without “falling apart” by actively and positively coping with stress.|
Identification of facial expressions of emotion (Ekman & Friesen, 1976) provided a series of 60 photographs of posed facial expressions comprising ten photographs each of six expressions (anger, disgust, fear, happiness, sadness, and surprise) posed by 10 actors. Stimuli were presented individually in a fixed, random order, and participants indicated for each which label best describes the emotion being expressed.
Quality of Life in Epilepsy 31 (QOLIE-31) (Cramer et al., 1998)is a validated 31-item self-report inventory that provides a quality of life T-score in people with epilepsy.
Testing was carried out individually during one session. After participants had given informed consent an interview established eligibility for the study and gathered demographic information (TLE and control groups) and details of seizure history (TLE group). The battery of tests was then administered in the order detailed in the Measures section. Assessments were administered according to their standardized instructions.
Scores on all measures are included in Table 1. Results of correlation analyses are presented in Table 3. Analysis confirmed that patient and control groups did not differ significantly for age. A two-way ANOVA (between subjects factor of group [TLE, control]; within subjects factor of test [Total EQ, WASI FSIQ]) indicated a significant group by test interaction (F[1,28]= 4.33, p = 0.047). Further planned comparisons indicated no significant difference between the groups on cognitive IQ. However, the TLE group was significantly impaired on the Total EQ score (t=−3.786, p < 0.001).
Table 3. Spearman's correlations between total EQ score and a range of other variables
|Premorbid IQ|| 0.212||0.261|
|Expression identification (errors)||−0.183||0.332|
|HADS anxiety|| 0.555||0.001|
|HADS depression||−0.743||<0.001 |
Correlation analyses revealed no significant relationship between FSIQ and EQ either across groups or within each group. Neither was there a significant relationship between premorbid IQ and Total EQ.
An independent t-test indicated that the TLE group made significantly more errors on the facial expression recognition task than the controls. Correlation analysis indicated no significant relationship between Total EQ score and mean number of errors on this task.
Independent t-tests indicated that the TLE group scored significantly higher on HADS Anxiety and Depression. Correlation analyses showed significant negative associations between Total EQ and both Anxiety and Depression, indicating that low EQ scores were associated with higher levels of psychological distress. To investigate the possibility that the group difference in Total EQ score could be accounted for by the fact that a General Mood score is included in the Total EQ score, analysis of covariance was carried out covarying HADS Anxiety and Depression scores. Although these analyses showed reductions in the magnitude of the between-group differences in Total EQ, they remained significant (Anxiety, F[1, 27]= 8.02, p = 0.009; Depression, F[1, 27]= 5.27, p = 0.030).
Correlation analysis showed no significant association between QOLIE-31 scores and Total EQ in the TLE group, although there was a trend for higher EQ to be associated with greater QoL.
Within the TLE group analyses confirmed no significant difference in Total EQ between patients with left versus right seizure onset. Neither was there any difference in Total EQ score between males and females or a significant interaction between sex and laterality of seizure onset. Finally there were no significant associations between Total EQ and either time since diagnosis or number of seizures per year.
A group of patients with TLE matched to a control group for age, and cognitive IQ were impaired on the EQ-i. They were also impaired on a task assessing the recognition of facial expressions. In neither the control group nor the patient group was IQ significantly related to EQ. However, EQ was significantly associated with distress measured using the HADS.
The results are consistent with the small number of existing studies investigating social cognition in people with TLE (Meletti et al., 2003; Reynders et al., 2005; Schacher et al., 2006; Shaw et al., 2007). They are also consistent with Bar On et al.'s (2003) proposal that EI is subserved by brain regions separate from those involved in cognitive intelligence and similar to those underlying social cognition. Together these results suggest that psychosocial problems identified in people with TLE might be conceptualized as consequences of low EI.
Suggestions that EI is positively associated with mental health (Taylor, 2001) were supported by findings of a negative relationship between Total EQ and HADS anxiety and depression scores. However, no causal relationship can be inferred from these results. Findings that group differences in EQ persisted even when differences in measures of anxiety and depression were taken into account suggest that the group difference in EI is not solely a function of the EQ-i's inclusion of mood in its total score.
Finally, we found that EI was not significantly related to QoL although there was a trend for this to be the case. It seems likely that such a relationship would have been identified had more participants been included in the study.
Although the results are consistent with existing evidence of neuropathological deficits further work is needed to clarify the role of seizure variables and the impact of living with a chronic illness. Future research should compare EI in patients with TLE with that in people with other epilepsies to determine whether a reduction in EI is specific to TLE and therefore more likely due to specific neuropathology.
We would like to thank Dr. Richard Grünewald, Dr. Markus Reuber, Dr. Stephen Howell, Professor Paul Griffiths, Dr. Charles Romanowski, and Dr. Elysa Widjaja, whose help was invaluable to this study.
Conflict of interest: We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. None of the authors of this study has any conflicts of interest in relation to this work.